Apparatus for producing composite filter plugs



Feb. 6, 1968 P. E. WISDOM 3,367,245

APPARATUS FOR PRODUCING COMPOSITE FILTER PLUGS Filed April 15, 1965 INVENTOR [Mfibu N\ N \N 0 3R? I 7 //M/ a who, 4-4

was M'f/M ATTORNEYS Uite tates atent O 3,367,245 APPARATUS BEER MKUBUCING COMPOSITE lFllLEER PLUGd Peter Edward Wisdom, London, England, assignor to The Molina Organisation Limited, London, England, a corporation of Great Britain Filed Apr. 13, 1965, Ser. No, 447,640 Claims priority, application Great Britain, Apr. 16, 1964, 15,8tl/ 64 5 (Ilaims. (Cl. 93-1) ABSTRACT 0F THE DISCLOSURE Apparatus for producing composite filter rod including powdered material is arranged to produce a succession of filter plugs on a moving continuous wrapper and deposit powdered material in regularly-spaced gaps between successive plugs, thereafter folding and securing the wrapper around the plugs and powdered material. The means for depositing the powdered material comprises a pocketed belt, each pocket being filled as it traverses an upper run and emptied as it passes along a lower run; positive ejection from the pockets is provided by reciprocable plungers.

This invention relates generally to apparatus for producing composite filter plugs for cigarettes and more particularly to apparatus for producing a complete filter rod having portions of powdered filter material interposed between conventional plugs at regular intervals.

In the manufacture of filter-tipped cigarettes, it is a common practice to produce a rod of filter material wrapped in paper and thereafter to cut such rod into lengths sutficient for individual cigarettes; not infrequently the rod is first cut into lengths suflicient to furnish tips for two cigarettes, each such double length then being placed between two cigarette lengths (i.e. lengths of tobacco wrapped in paper) and united therewith by a suitable band, whereafter the double-length portion of rod is cut in half to yield two tipped cigarettes. Such rods of filter material have been made as composite rods, i.e. containing two or more kinds of filter material, as for example one kind of filter material selected solely for its filtering efiiciency, and another kind of filtering material selected for its attractive appearance, the rod being then made and applied to cigarette lengths in such manner that the latter filter material appears at the end of the finished cigarette while the former filter material is interposed between the latter filter material and the tobacco.

Until recently, however, the filter materials employed have been relatively coherent materials, e.g. paper or cotton wool, but demand for more efiicient filtration has now led to the employment of powdered material, e.g. granules of activated carbon. With such material, it will be appreciated that there are practical difficulties in following the conventional practice of first forming short plugs of each filter material and then marshalling such plugs to form a filter rod, even though some conventional plugs are still required, as powdered material is not suitable for the exposed end of a cigarette.

The present invention stems from, and comprises an improvement in or modification of, the invention disclosed in copending application Serial No. 400,862 filed October 1, 1964, now US. Patent No. 3,312,152, issued April 4, 1967. In that application, the invention disclosed is broadly defined as apparatus for producing composite filter rod including portions of powdered material, comprising means for feeding filter plugs in succession on to a continuous Wrapper with gaps between successive plugs at regular intervals, means for filling said gaps with powdered material, and means for folding said wrapper Patented Feb. 6, 1958 "ice around said plugs and said material to form a continuous rod.

A preferred form of the aforesaid invention of said copending application is also disclosed therein; in said preferred form, the plug feeding means is arranged to move the plugs and the wrapper substantially horizontally through a loading zone, and the filling means comprises an endless flexible conveyor band having regularly spaced carrier pockets therein, said band being so arranged that a lower run of the band travels through the loading zone immediately above said plugs with the pockets facing downward above the gaps between successive plugs, further means being provided for filling each of said pockets with the powdered material between successive passages of the pocket through the loading Zone.

The filling and emptying of the pockets in the band may be done by gravity only, if the speed of operation and the lengths of the runs of the band allow sufficient time but in the said copending application it is recognized that provision may be made to accelerate emptying and filling of said pockets, if for example it is desired to shorten the runs of the band to make the whole apparatus more compact.

It is an object of the present invention to provide apparatus with which filter rod containing powdered material may be made, which apparatus while largely similar to that of the said copending application provides for accelerated emptying of pockets.

According to the invention, apparatus is provided for producing composite filter rod including portions of pOW- dered filter material, comprising means for feeding filter plugs in succession onto a continuous wrapper with gaps between successive plugs at regular intervals and moving the plugs and the wrapper substantially horizontally through a loading zone, means for filling said gaps with powdered material comprising an endless flexible conveyor band having regularly spaced pockets therein and so arranged that a lower run of said band travels through the loading zone immediately above said plug with the pockets facing downwardly above said gaps, and further means for filling each of said pockets with the powdered material between successive passages of the pocket through the loading zone, including ejection means associated with each of said pockets and arranged to effect positive ejection of powdered material from the pocket during passage of the pocket through the loading zone.

Preferably the ejection means for each pocket comprises a plunger reciprocable in the pocket and arranged to move progressively from a retracted position to an advanced position as the pocket passes through the loading zone; in the advanced position the plunger may effectively fill the pocket while in the retracted position it merely constitutes an end wall of the pocket.

Such plungers may be caused to reciprocate in their associated pockets by various means; where as is most usual the conveyor band is so supported as to have upper and lower horizontal runs connected by semi-cylindrical sections, we may provide vertical plates extending across the edges of the band, with channels on the inner faces of said plates receiving lugs on the sides of the plungers. The said channels them serve as cams and are so formed relative to the configuration of the band as to produce desired reciprocation of the plungers as they move with the band.

In order that the invention may be well understood a preferred embodiment thereof will now be described, reference being made to the accompanying drawings, in which:

FIGURE 1 is a side elevation of the relevant parts of an apparatus embodying the present invention, in section on the plane indicated by line II of FIGURE 2; and

FIGURE 2 is an end view of the same apparatus, in section on the plane indicated by line IIII of FIG- URE 1.

The apparatus shown comprises a horizontal bed 1 on which an endless conveyor belt 2 travels, said belt having a return run (not shown) below the bed 1 from which return run the belt regains the upper surface of the bed 1 via a guide pulley 3. A continuous paper strip 4 is fed on to the bed 1 via a further guide pulley 5, the relative positions of said guide pulleys being such that the belt 2 is fed between the paper strip 4 and the bed 1 so that the belt supports and propels the strip.

Any conventional form of plug-feeding mechanism diagrammatically shown at FF is arranged to supply a succession of conventional filter plugs P to the bed 1; said plugs P are fed in the same direction as the paper strip 4 and belt 2 so as to be carried with said strip and belt, maintaining regularly-spaced gaps between successive plugs. (Although as shown in FIGURE 1 there is a gap between each plug and its successor, if desired the gaps may occur at longer intervals, e.g. there may be two or three abutted plugs between each gap and the next.)

The top surface of the bed 1 is flat in the region (to the right in FIGURE 1) where the plugs P, strip 4 and belt 2 are fed on to it. To the left (as seen in FIGURE 1) of the pulley 3, the top surface of the bed assumes a flattened-V configuration (see FIGURE 2) so as to lift the edges of belt 2 and strip 4 to approximately the height of the top of plugs P; the transition from flat to flattened- V configuration occurs over a length approximately equal to the length of two plugs, P, as indicated by lines 6, 7 (representing the edges of the strip and of the belt respectively).

Above the bed 1 is carried an endless flexible band having a horizontal lower run 8, in which the band lies immediately above the plugs P, and a horizontal upper run 9; said band moves clockwise (as viewed in FIG- URE 1) and traverses semicircular paths in passing be tween its upper and lower runs so as to form a horizontally-elongated loop. The said band is of articulated construction, comprising rubber blocks 10 alternating with metal pockets 11; each pocket 11 comprises a tube of rectangular cross-section having on opposed faces and at its outer end (outer" in relation to the loop formed by said band) a pair of lugs 12, each lug 12 being embedded in and bonded to a different one of the two adjacent rubber blocks 10. The lugs 12 are, therefore, disposed fore and aft of each tube, in relation to the direction of travel of the band, and in between said lugs, i.e. on its sides relative to said direction of travel, but further inward (in relation to the loop) each tube is secured to two endless roller chains 13 forming loops somewhat smaller than that formed by the band.

Side plates 14 are mounted vertically on either side of the band and chains to enclose said band and chains substantially completely, except for the underside of the lower run 8 of the band and the upper surface of the upper run thereof. Said plates 14 have inwardly directed flanges 15, which meet one another, around the curved portions of the band; said flanges are very close to, preferably lightly touching, the band so as to prevent escape of powder from the pockets 11 as the latter traverse said curved portions. Above the upper run 9 of the band, the flanges 15 are narrower than elsewhere, as indicated at 15a (FIGURE 2), and between them is accommodated the lower end of a powder reservoir 16; said reservoir is tapered downwardly so as to have a bottom discharge opening 17 of width equal to the interior diameter of the pockets 11 of the band.

The chains 13 carry a series of balls 18 resting in recesses 19 in the outer sides of the chains (i.e. the sides adjacent to side plates 14), and each of the plates 14 has a groove 20 into which the balls 18 project; the form of grooves 20, as viewed from the side, determines the form of loop maintained by said chains (and hence the form of loop in which the band is held).

In each pocket 11 a reciprocable plunger 21 is contained, the plungers being rather longer than the associated pockets. Within the loop defined by chains 13 and grooves 20, plates 14 each have an inwardly extending rib 22, these ribs being of such depth as to leave between their opposed faces 23 a sufiicient clearance for the plungers 21. Said faces 23 are grooved as indicated at 24 and recesses in the sides of plungers 21 contain balls 25 which are also received in the grooves 24.

A drive shaft 26 extends through both side plates 14, normal to said plates, and carries two sprockets 27 engaging the two chains 13; in operation of the apparatus, the shaft 26 is driven clockwise (as seen in FIGURE 1) to produce rotation of the chains 13, and hence of the band, in the same sense.

When the band is thus moved, it will be appreciated that each of the pockets 11 moves along a path defined by grooves 18. The plunger 21 associated with each pocket moves along a path defined by grooves 24. Inspection of FIGURE 1 will show that, while the grooves 18 define a symmetrical path, comprising mutually equal upper and lower horizontal lengths connected by equal semicircles, the grooves 24 define an asymmetric path, comprising an upper horizontal length, a lower straight length which is inclined so as to be higher at the right-hand end than at the left-hand end, and dissimilar circular arcs connecting the upper and lower lengths, the right-hand one being of less than the left-hand one of correspondingly more than 180, and the former are being of smaller radius than the latter.

It will be appreciated that any given plunger 21 will, as it and its associated pocket 11 are in any selected position during rotation of the band and chains, be in a position relative to said associated pocket which is determined by the spacing between the grooves 18 and 24 at said selected position. As the different forms of grooves 18 and 24 cause said spacing to vary, the plungers 21 will reciprocate in their pockets 11. With the disposition of the grooves as shown as each pocket 11 traverses the upper run 9 its plunger 21 will be largely withdrawn from the pocket and powdered filter material from the reservoir 16 will fill the pocket. As the filled pocket is then moved round the semi-circle at the right-hand end of the assembly, the relative positions of the plunger and pocket will not change, and the pocket remains full of the powdered material (flanges 15 preventing spillage). As the full pocket traverses the lower run 8, however, the plunger 21 is constrained to enter the pocket progressively until, at the left-hand end of the lower run, the plunger nearly fills the pocket; the powdered filter material is thus positively ejected from the pocket and enters one of the gaps between successive plugs P, which will be travelling below the pocket.

As the pocket 11, new empty, moves in an arcuate path at the left-hand end of the assembly, to return to the upper run 9, the plunger 21 is withdrawn to restore the original relationship to these parts to permit another filling of the pocket with powdered filter material.

It will be seen that the apparatus shown and described makes possible the continuous production of filter rod containing portions of powdered material in an efficient manner, even where the operating speed required is high. The positive ejection of the powdered material from the pockets assists materially in avoiding uneven filling of the gaps. between plugs P, which with non-positive emptying of the pockets could occur whenever the powdered material tended to stick to the walls of said pockets.

For completeness, it should be added that the paper strip 4, carrying the plugs P and intervening portions of powdered material, is carried by the belt 2 to the left (as seen in FIGURE 1) and brought to a conventional garniture indicated diagrammaticaly at G, i.e. a folding device which completes the folding of the strip 2, applying adhesive to an overlapped edge portion thereof, to form a cylinder of paper around the plugs P and powdered material; thereafter the rod so formed is cut into such lengths as are convenient. Such garnitures and cutting mechanism are well known in the art and therefore need not be described in detail here.

The apparatus described in detail is, of course, only one preferred embodiment of the invention, various changes in its details being possible without departure from the scope of the invention.

I claim:

1. Apparatus for producing composite filter rod including portions of powdered filter materal, comprising means for feeding filter plugs in succession on to a continuous wrapper with gaps between successive plugs at regular intervals and moving the plugs and the wrapper substantially horizontally through a loading zone, means for filling said gaps with powdered material comprising an endless flexible conveyor band having regularly-spaced pockets therein and so arranged that a lower run of said band travels through the loading zone immediately above said plugs with the pockets facing downwardly above said gaps, further means for filling each of said pockets with the powdered material between successive passages of the pocket through the loading zone, ejection means associated with each of said pockets and arranged to effect positive ejection of powdered material from the pocket during passage of the pocket through the loading zone, and garniture means for continuously folding and securing said wrapper around the plugs and powdered material to form a continuous filter rod.

2. Apparatus as claimed in claim 1, in which the ejection means for each pocket comprises a plunger reciprocable in the pocket and arranged to move progressively from a retracted position in which it constitutes an end wall of the pocket to an advanced position in which it effectively fills the pocket as the pocket passes through the loading zone.

3. Apparatus as claimed in claim 2, including lugs on the sides of said plungers and vertical plates extending across the edges of the conveyor band, said plates having channels on their inner faces to receive said lugs, said channels being arranged to serve as cams so formed relative to the configuration of the band as to produce desired reciprocation of the plungers as they move with said band.

4. Apparatus as claimed in claim 3 in which the conveyor band is of articulated construction and comprises alternate resilient blocks and rigid pockets of tube-like form, said pockets also being secured to a pair of endless roller chains.

5. Apparatus as claimed in 4 in which said blocks are of rubber and said pockets comprise metal tubes of rectangular section, each tube having one of its ends secured between a pair of the blocks and its other end secured to said chains.

References Cited UNITED STATES PATENTS 2,248,311 7/1941 Skoog 2222l7X 3,259,029 7/1966 Hall et al. 93-1 BERNARD STICKNEY, Primary Examiner. 

